A model for mercuric ion reduction in recombinant Escherichia coli

Plasmid‐encoded mercuric reduction involves transfer of Hg²⁺ across the cellular envelope and reduction to Hg⁰ by the cytoplasmic mercuric reductase using NADPH. A mathematical model was developed for the binding and transfer of Hg²⁺ by transport proteins and the subsequent reduction of Hg²⁺. The values of the model parameters were determined using experimental data. The derived rate expressions were similar to the previously experimentally determined ones. The model predicted that a differential amplification of the transport protein relative to mercuric reductase expression levels may enhance the Hg²⁺ reduction rate in whole cells.